The invention relates to a label ejection device, a labeling printing system comprising said device and a method for discarding labels, in particular self-adhesive labels. The invention is concerned in particular with preventing faulty labels from being applied to items (or containers containing such items), with minimal attendant interruption of machine operation.
Packagers of foods, pharmaceuticals and as well as the tax stamp industry, demand high level of accuracy and reliability in the labeling process.
There are number of labeling systems adapted to apply pressure-sensitive labels to articles or containers at a label applying station. Labels are carried initially by a supporting tape with the adhesive side of the label facing toward the supporting tape.
The labels precisely contain information relating to the products contained in said containers, giving basic information about the product, such as for example the commercial name and/or a distinguishing image, the number of the production batch, the capacity of the product, the chemical composition, the dates of packaging and expiration, or similar.
The effective labeling systems and equipment are not perfect and, on occasion, “incorrect” or faulty labels may be applied to containers. Incorrect/faulty labels are wrong labels or labels with poor or illegible lot numbers, or with secure features badly printed. This is a matter of particular concern to packagers. An incorrectly labeled container could lead to a costly product recall, and might result in serious injury. Accordingly, equipment and systems have been developed for detecting the presence of incorrect/faulty labels using several types of sensors, trigger, captors and cameras well known from those skilled in the art. Labeling machines that provide labeling error detection prior to the application of the labels onto the containers are preferred to those which provide error detection following application.
In particular, a faulty label ejection device may be associated to a labeling printing system to provide packagers with rolls of security printed labels with only self-adhesive labels correctly printed. Thus, it is necessary to prevent a faulty label from being applied on a container.
WO 2008/055052 discloses an incorrect label removal system for removing unwanted labels from a web of labels in a labeling machine. The incorrect label removal system includes a label peel assembly positioned between two fixed points along the direction of travel of the web of labels. The label peel assembly provides a first orientation in which labels remain on the web as the web passes the label assembly, and selectively provides a second orientation in which labels are removed from the web. The label peel assembly provides that a length of the web between the two fixed points is substantially the same when the label peel assembly is in each of the first orientation and the second orientation.
GB 2 425 298 discloses a peel plate for labeling retractable when label defective. Said peel plate assembly functions in a normal position of the plate being extended for the purposes of peeling adhesive labels from a supply web and directing them toward containers, but can be retracted selectively when a label is identified as incorrect or faulty, thereby leaving faulty or incorrect labels on the label supply web at least until they are removed from the active site of label application. When the peel plate and its supporting Nock are retracted from the normal position shown, the web passes around a roller which has no sharp edge to cause peeling. Defective labels are detected by a scanner connected to a central processing unit.
WO 2008/012633 discloses an apparatus and method for rejecting irregular or faulty labels. An apparatus has a removing unit for removing an altered or faulty self-sticking label applied on a supporting tape of labels moving along an advancing direction. The collecting unit includes another supporting tape for supporting the self-sticking label. A supporting unit is arranged for supporting the removing unit and the collecting unit. The removing unit comprises removing means for removing said altered or faulty labels from said supporting tape and collecting means arranged for receiving said altered labels from said removing means; said collecting means comprises a further supporting tape suitable for supporting and collecting said altered labels.
The removing means comprises separating means arranged for cooperating with sucking element for separating the faulty labels from the primer supporting tape, said separating means being opposed to the sucking means.
A collecting unit is arranged for receiving the self-sticking label from the removing unit. The collecting unit includes another supporting tape for supporting the self-sticking label. A supporting unit is arranged for supporting the removing unit and the collecting unit. A moving unit is supported by the supporting unit, and arranged for moving the latter supporting tape along an advancing direction with a desired operating speed.
The apparatus prevents the altered or faulty self-sticking label from being applied to cylindrical containers. The apparatus allows the altered or faulty self-sticking label to be more easily identified for discarding the self-sticking label.
Apparatus for discarding labels is arranged for removing from the supporting tape non-satisfying labels, for example because provided with faded or unreadable printing, before being applied on a respective container.
Said apparatus comprises a peel plate, bedplate or separating means supporting an operating group and a collecting group. Said operating group comprises an operating roller cooperating with removing means arranged for removing the faulty labels from the supporting tape and transferring said faulty labels on the collecting group. Said collecting group comprises two rollers which of them is free to rotate for collecting faulty labels.
When the discarding apparatus detects, by means of a sensor, the presence of a faulty label, a control unit actuates the operating group, which removes such label from the supporting tape. The faulty label, gradually detached from the supporting tape, is stuck on the collecting roller. Thus, said collecting roller accumulates a plurality of faulty labels increasing consequently its own diameter up to a limit value established by an operator. Once such limit value has been reached, the operator removes and substitutes the collecting roller.
We met some issues in the apparatus of the prior art. The apparatuses disclosed for discarding and recovering labels associated with labeling machines comprise a peel plate or separating means. At the detection of a faulty label by standard detection means such as captor or camera, the position of the faulty label is calculated on the supporting tape for removing said faulty label detected, depending on the label's length, the space between two labels, and the number of labels in front of the faulty label. The peel plate or separating means is performed on an active position to remove the said faulty label from the supporting tape. A friction occurs on the supporting tape providing with a tension which could lead sometimes to a rupture of the said primer supporting tape. A deformation and damage of the supporting tape occurs after each removal of faulty label leading to a position's imprecision of the labels more and more important. An adjustment of the detection means is necessary to redefine the exact positions of the next labels printed.
There is an interruption of the applying label station and sometimes if a rupture of the supporting label happens, a complete change of the roll of labels already printed is necessary.
In addition, during the separation of the faulty label from the primer supporting tape, there are some vibrations of the supporting tape itself leading also to adjustment issue. The tension of the supporting tape between the supporting rollers is less tightened.
All cases lead to a remarkable waste of time and money so as to obtain a new correct positioning of labels. The move of the primer supporting tape along the advancing direction at a high speed is not possible due to all adjustments necessary.
Said previously cited issues of the label ejection device disclosed in the state of the art lead to additional issues when the said device is associated to a labeling printing system comprising a printing device, such as for example an inkjet printer, being able to print out on the blank labels. Indeed, a gap in the positioning of the labels leads to a print out badly performed on the next blank label. A succession of ejection of label badly printed is happened in the absence of a manual adjustment of the sheet like support before the printing device and the detection means. The print out of secure labels on a supporting tape with complex security features requires a high quality of print with an important precision in the positioning. Said print out may need several types of ink, some various printer such as inkjet printer and potentially some additional device such as UV dryer so as to limit set off after potential winding of the labels in a collecting roller for delivery to a packagers. The previously constraints cited and a processing of the printing labeling system at a high speed are not possible with the existing apparatuses for discarding faulty labels.
An object of the present invention is to improve the apparatuses, systems and methods for discarding and collecting labels, in particular self-adhesive labels.
There is a need, therefore, for an improved label ejection device and an improved labeling printing system that more efficiently and effectively removes labels from a sheet like support.